United Kingdom
Economic Value Creation of Artificial Intelligence in Supporting Variable Renewable Energy Resource Integration to Power Systems: A Systematic Review
Mar 2025
Publication
The integration of Variable Renewable Energy (VRE) sources in power systems is increased for a sustainable environment. However due to the intermittent nature of VRE sources formulating efficient economic dispatching strategies becomes challenging. This systematic review aims to elucidate the economic value creation of Artificial Intelligence (AI) in supporting the integration of VRE sources into power systems by reviewing the role of AI in mitigating costs related to balancing profile and grid with a focus on its applications for generation and demand forecasting market design demand response storage solutions power quality enhancement and predictive maintenance. The proposed study evaluates the AI potential in economic efficiency and operational reliability improvement by analyzing the use cases with various Renewable Energy Resources (RERs) including wind solar geothermal hydro ocean bioenergy hydrogen and hybrid systems. Furthermore the study also highlights the development and limitations of AI-driven approaches in renewable energy sector. The findings of this review aim to highlight AI’s critical role in optimizing VRE integration ultimately informing policymakers researchers and industry stakeholders about the potential of AI for an economically sustainable and resilient energy infrastructure.
Medium Speed Lean Hydrogen Engine Modelling and Validation
Sep 2025
Publication
Hydrogen spark-ignition direct-injection engines result in no carbon emissions at use but NOX remains a challenge. This study demonstrates that with lean combustion (ϕ < 0.38) in-cylinder NOX can be reduced to a quarter of the current maritime regulatory limit. An original contribution of this work is the use of speciesresolved emissions formation across multiple engine load conditions. A novel chemically detailed combustion modelling framework was developed in CHEMKIN-Pro incorporating the evolution of the CRECK C1–C3 NOX mechanism for improved high-pressure accuracy. The framework was extensively validated using crank-angleresolved data across 9–18 bar loads. The model accurately reproduced pressure traces heat release angles and NOX. Mechanistic analysis revealed a shift from thermal Zeldovich NOX to intermediate-species (notably N2Odriven) as equivalence ratio and pressure varied. The findings highlighted the use of a high-fidelity chemical kinetic modelling framework not only to match experimental results but to gain physically grounded insight into actionable near-zero emission strategies.
Numerical Investigation of Premixed Hydrogen Combustion in Dual-fuel Marine Engines at High Load
Jun 2025
Publication
Zero-emission fuels are expected to drive the maritime sector decarbonisation with hydrogen emerging as a long-term solution. This study aims to investigate by using CFD modelling a hydrogen fuelled marine dual-fuel engine to identify operating settings ranges for different hydrogen energy fractions (HEF) as well as parametrically optimise the diesel fuel injection timing and temperature at inlet valve closing (IVC). A large marine four-stroke engine with nominal power of 10.5 MW at 500 rev/m is considered assuming operation at 90 % load and hydrogen injection in the cylinders intake ports. CFD models are developed for several operating scenarios in both diesel and dual-fuel modes. The models are validated against measured data for the engine diesel mode and literature data for a hydrogen-fuelled light-duty engine. A convergence study is conducted to select the grid compromising between computational effort and accuracy. Parametric runs for 20 % 40 % and 60 % HEF with different IVC temperature and diesel start of injection are modelled to quantify the engine performance emissions and combustion characteristics. A single parameter optimisation is conducted to determine the most effective pilot diesel injection timings. The results reveal the IVC temperature range for stable hydrogen combustion to avoid incomplete combustion at low IVC temperature and knocking above 360 K. The proposed settings lead to higher peak heat release rate and in-cylinder pressure compared to the diesel mode without exceeding the permissible in-cylinder pressure rise limits for 60 % HEF. However NOx emissions increase to 12.9 g/kWh in the dual-fuel mode. The optimal start of injection (SOI) for the diesel fuel in the case of 60 % HEF is found 8 ◦CA BTDC resulting in an indicated thermal efficiency of 43.2 % and stable combustion. Advancing SOI beyond the optimal value results in incomplete combustion. This is the first study on hydrogen use in large marine four-stroke engines providing insights for the engine design and operation and as such it contributes to the maritime industry decarbonisation efforts.
A Cost-Optimizing Analysis of Energy Storage Technologies and Transmission Lines for Decarbonizing the UK Power System by 2035
Mar 2025
Publication
The UK net zero strategy aims to fully decarbonize the power system by 2035 anticipating a 40–60% increase in demand due to the growing electrification of the transport and heating sectors over the next thirteen years. This paper provides a detailed technical and economic analysis of the role of energy storage technologies and transmission lines in balancing the power system amidst large shares of intermittent renewable energy generation. The analysis is conducted using the cost-optimizing energy system modelling framework REMix developed by the German Aerospace Center (DLR). The obtained results of multiple optimization scenarios indicate that achieving the lowest system cost with a 73% share of electricity generated by renewable energy sources is feasible only if planning rules in England and Wales are flexible enough to allow the construction of 53 GW of onshore wind capacity. This flexibility would enable the UK to become a net electricity exporter assuming an electricity trading market with neighbouring countries. Depending on the scenario 2.4–11.8 TWh of energy storage supplies an average of 11% of the electricity feed-in with underground hydrogen storage representing more than 80% of that total capacity. In terms of storage converter capacity the optimal mix ranges from 32 to 34 GW of lithium-ion batteries 13 to 22 GW of adiabatic compressed air energy storage 4 to 24 GW of underground hydrogen storage and 6 GW of pumped hydro. Decarbonizing the UK power system by 2035 is estimated to cost $37–56 billion USD with energy storage accounting for 38% of the total system cost. Transmission lines supply 10–17% of the total electricity feed-in demonstrating that when coupled with energy storage it is possible to reduce the installed capacity of conventional power plants by increasing the utilization of remote renewable generation assets and avoiding curtailment during peak generation times.
Which Offers Greater Techno-Economic Potential: Oil or Hydrogen Production from Light Oil Reservoirs?
Jun 2025
Publication
The global emphasis on clean energy has increased interest in producing hydrogen from petroleum reservoirs through in situ combustion-based processes. While field practices have demonstrated the feasibility of co-producing hydrogen and oil the question of which offers greater economic potential oil or hydrogen remains central to ongoing discussions especially as researchers explore ways to produce hydrogen exclusively from petroleum reservoirs. This study presents the first integrated techno-economic model comparing oil and hydrogen production under varying injection strategies using CMG STARS for reservoir simulations and GoldSim for economic modeling. Key technical factors including injection compositions well configurations reservoir heterogeneity and formation damage (issues not addressed in previous studies) were analyzed for their impact on hydrogen yield and profitability. The results indicate that CO2-enriched injection strategies enhance hydrogen production but are economically constrained by the high costs of CO2 procurement and recycling. In contrast air injection although less efficient in hydrogen yield provides a more cost-effective alternative. Despite the technological promise of hydrogen oil revenue remains the dominant economic driver with hydrogen co-production facing significant economic challenges unless supported by policy incentives or advancements in gas lifting separation and storage technologies. This study highlights the economic trade-offs and strategic considerations crucial for integrating hydrogen production into conventional petroleum extraction offering valuable insights for optimizing hydrogen co-production in the context of a sustainable energy transition. Additionally while the present work focuses on oil reservoirs future research should extend the approach to natural gas and gas condensate reservoirs which may offer more favorable conditions for hydrogen generation.
Towards Decarbonizing Gas: A Generic Optimal Gas Flow Model with Linepack Constraints for Assessing the Feasibility of Hydrogen Blending in Existing Gas Networks
Aug 2025
Publication
Hydrogen blending into natural gas networks is a promising pathway to decarbonize the gas sector but requires bespoke fluid-dynamic models to accurately capture the properties of hydrogen and assess its feasibility. This paper introduces a generalizable optimal transient gas flow model for transporting homogeneous natural gashydrogen mixtures in large-scale networks. Designed for preliminary planning the model assesses whether a network can operate under a given hydrogen blending ratio without violating existing constraints such as pressure limits pipeline and compressor capacity. A distinguishing feature of the model is a multi-day linepack management strategy that engenders realistic linepack profiles by precluding mathematically feasible but operationally unrealistic solutions thereby accurately reflecting the flexibility of the gas system. The model is demonstrated on Western Australia’s 7560 km transmission network using real system topology and demand data from several representative days in 2022. Findings reveal that the system can accommodate up to 20 % mol hydrogen potentially decarbonizing 7.80 % of gas demand.
An Overview of the Hydrogen Value Chain in Energy Transitioning Economies: A Focus on India
Oct 2025
Publication
India’s energy sector is undergoing a major transformation as the nation targets energy independence by 2047 and net-zero emissions by 2070. With a high dependency on energy imports a strategic shift toward renewable energy and decarbonisation is crucial. Hydrogen has emerged as a promising solution to address energy storage and sustainability challenges prompting emerging countries to develop strong hydrogen infrastructures. This paper examines various methods involved in the hydrogen value chain from production to utilisation from the perspective of transitioning economies. By identifying key parameters and existing gaps this paper aims to support policymakers and stakeholders in designing effective strategies to accelerate the development of a sustainable and secure hydrogen economy. India currently relies on carbon-intensive hydrogen from fossil fuels. Green hydrogen faces high costs and infrastructure gaps. Despite storage and safety concerns hydrogen shows strong potential for clean energy and industry transformation.
Assessing Hydrogen Supply and Demand in the Liverpool City Region: A Regional Development Review from Stakeholders' Perspective
Oct 2025
Publication
Under the UK’s carbon neutrality goals for 2050 the Liverpool City Region’s (LCR) strategic positioning with its rich industrial heritage and infrastructure assets such as extensive port facilities and proximity to vast renewable energy resources positions it as a potential leader in the UK’s shift towards a hydrogen economy. Given this the regional hydrogen industry and stakeholders in decarbonisation initiatives intend to undertake a critical review of the opportunities challenges and uncertainties to local hydrogen supply and demand systems to assist in their decision-making. To achieve this goal this study reviews the readiness of the hydrogen supply chain infrastructure within the LCR which highlights four sectors in the hydrogen economy i.e. production storage transportation and utilisation. Subsequently to offer the first-hand data in practice a multi-faceted approach that incorporates a broad array of stakeholders through the Triple Helix (TH) model is adopted. Special attention is given to hydrogen’s role in transforming heavy industry transportation and heating sectors supported by significant local projects like HyNet North West. During a roundtable discussion industry-academia-government stakeholders identify challenges in scaling up infrastructure and assess the economic and technological landscape for hydrogen adoption. To the best of our knowledge this will be the first regional academic endeavour to comprehensively examine the alignment between hydrogen supply and demand theory and practice. Based on a detailed SWOT analysis this study outlines the region’s strengths including established industrial clusters and technological capabilities in manufacturing. It also highlights weaknesses such as the high costs associated with emerging hydrogen technologies technological immaturity and gaps in necessary infrastructure. The opportunities presented by national policy incentives and growing global demand for sustainable energy solutions are considered alongside threats including regulatory complexities and the slow pace of public acceptance. This comprehensive examination not only maps the current landscape but also sets the stage for strategic interventions needed to realise hydrogen’s full potential within the LCR aiming to guide policymakers industry leaders and researchers in their efforts to foster a viable hydrogen economy. Moreover the findings offer valuable insights that can inform the development of hydrogen strategies in other regions and cities.
Above-ground Hydrogen Storage: A State-of-the-art Review
Oct 2024
Publication
Hydrogen is increasingly recognized as a clean energy alternative offering effective storage solutions for widespread adoption. Advancements in storage electrolysis and fuel cell technologies position hydrogen as a pathway toward cleaner more efficient and resilient energy solutions across various sectors. However challenges like infrastructure development cost-effectiveness and system integration must be addressed. This review comprehensively examines above-ground hydrogen storage technologies and their applications. It highlights the importance of established hydrogen fuel cell infrastructure particularly in gaseous and LH2 systems. The review favors material-based storage for medium- and long-term needs addressing challenges like adverse thermodynamics and kinetics for metal hydrides. It explores hydrogen storage applications in mobile and stationary sectors including fuel-cell electric vehicles aviation maritime power generation systems off-grid stations power backups and combined renewable energy systems. The paper underscores hydrogen’s potential to revolutionize stationary applications and co-generation systems highlighting its significant role in future energy landscapes.
Development and Validation of an All-metal Scroll Pump for PEM Fuel Cell Hydrogen Recirculation
Oct 2025
Publication
Hydrogen recirculation is essential for maintaining fuel efficiency and durability in Proton Exchange Membrane Fuel Cell (PEMFC) systems particularly in automotive range extender applications. This study presents the design simulation and experimental validation of a dry all-metal scroll pump developed for hydrogen recirculation in a 5 kW PEMFC system. The pump operates without oil or polymer seals offering long-term compatibility with dry hydrogen. Two prototypes were fabricated: SP1 incorporating PTFE-bronze tip seals and SP2 a fully metallic seal-free design. A fully deterministic one-dimensional (1D) model was developed to predict thermodynamic performance including leakage and heat transfer effects and validated against experimental results. SP1 achieved higher flow rates due to reduced axial leakage but experienced elevated friction and temperature. In contrast SP2 provided improved thermal stability and lower friction with slightly reduced flow performance. The pump demonstrated a maximum flow rate of 50 l/min and an isentropic efficiency of 82.2 % at 2.5 bara outlet pressure. Simulated performance showed strong agreement with experimental results with deviations under 5 %. The findings highlight the critical role of thermal management and manufacturing tolerances in dry scroll pump design. The seal-free liquid-cooled scroll architecture presents a promising solution for compact oil-free hydrogen recirculation in low-power fuel cell systems.
Techno-Economic Evaluation of a Floating Photovoltaic-Powered Green Hydrogen for FCEV for Different Köppen Climates
Sep 2025
Publication
The escalating global demand for electricity coupled with environmental concerns and economic considerations has driven the exploration of alternative energy sources creating competition for land with other sectors. A comprehensive analysis of a 10 MW floating photovoltaic (FPV) system deployed across different Köppen climate zones along with techno-economic analysis involves evaluating technical efficiency and economic viability. Technical parameters are assessed using PVsyst simulation and HOMER Pro. While economic analysis considers return on investment net present value internal rate of return and payback period. Results indicate that temperate and dry zones exhibit significant electricity generation potential from an FPV. The study outlines the payback period with the lowest being 5.7 years emphasizing the system’s environmental benefits by reducing water loss in the form of evaporation. The system is further integrated with hydrogen generation while estimating the number of cars that can be refueled at each location with the highest amount of hydrogen production being 292817 kg/year refueling more than 100 cars per day. This leads to an LCOH of GBP 2.84/kg for 20 years. Additionally the comparison across different Koppen climate zones suggests that even with the high soiling losses dry climate has substantial potential; producing up to 18829587 kWh/year of electricity and 292817 kg/year of hydrogen. However factors such as high inflation can reduce the return on investment to as low as 13.8%. The integration of FPV with hydropower plants is suggested for enhanced power generation reaffirming its potential to contribute to a sustainable energy future while addressing the UN’s SDG7 SDG9 SDG13 and SDG15.
Development of the Hydrogen Market and Local Green Hydrogen Offtake in Africa
Jun 2025
Publication
Creating a hydrogen market in Africa is a great opportunity to assist in the promotion of sustainable energy solutions and economic growth. This article addresses the legislation and regulations that need to be developed to facilitate growth in the hydrogen market and allow local green hydrogen offtake across the continent. By reviewing current policy and strategy within particular African countries and best practices globally from key hydrogen economies the review establishes compelling issues challenges and opportunities unique to Africa. The study identifies the immense potential in Africa for renewable energy and in particular for solar and wind as the foundation for the production of green hydrogen. It examines how effective policy frameworks can establish a vibrant hydrogen economy by bridging infrastructural gaps cost hurdles and regulatory barriers. The paper also addresses how local offtake contracts for green hydrogen can be used to stimulate economic diversification energy security and sustainable development. Policy advice is provided to assist African authorities and stakeholders in the deployment of enabling regulatory frameworks and the mobilization of funds. The paper contributes to global hydrogen energy discussions by introducing Africa as an eligible stakeholder in the emerging hydrogen economy and outlining prospects for its inclusion into regional and global energy supply chains.
Polymers and Composites for Hydrogen Economy: A Perspective
Oct 2025
Publication
This paper provides authors’ perspective on the current advances and challenges in utilising polymers and composites in hydrogen economy. It has originated from ‘Polymers and Composites for Hydrogen Economy’ symposium organised in March 2025 at the University of Warwick. This paper presents views from the event and thus provides a perspective from academia and industry on the ongoing advances and challenges for those materials in hydrogen applications.
Solar Enabled Pathway to Large-scale Green Hydrogen Production and Storage: A Framework for Oman's Advancing Renewable Energy Goals
Aug 2025
Publication
The utilisation of renewable energy sources for hydrogen production is increasingly vital for ensuring the long-term sustainability of global energy systems. Currently the Sultanate of Oman is actively integrating renewable energy particularly through the deployment of solar photovoltaic (PV) systems as part of its ambitious targets for the forthcoming decades. Also Oman has target to achieve 1 million tonnes of green-H2 production annually. Leveraging Oman's abundant solar resources to produce green hydrogen and promote the clean transportation industry could significantly boost the country's sustainable energy sector. This paper outlines a standalone bifacial solar-powered system designed for large-scale green hydrogen (H2) production and storage to operate both a hydrogen refuelling station and an electric vehicle charging station in Sohar Oman. Using HOMER software three scenarios: PV/Hydrogen/Battery PV/Hydrogen PV/Battery systems were compared from a techno-economic perspective. Also the night-time operation (Battery/Hydrogen) was investigated. Varying cost of electricity were obtained depending on the system from $3.91/kWh to $0.0000565kWh while the bifacial PV/Hydrogen/Battery system emerged as the most efficient option boasting a unit cost of electricity (COE) of $3.91/kWh and a levelized cost of hydrogen (LCOH) value of $6.63/kg with net present cost 199M. This system aligns well with Oman's 2030 objectives with the capacity to generate 1 million tonnes of green-H2 annually. Additionally the findings show that the surplus electricity from the system could potentially cover over 30% of Oman's total energy consumption with zero harmful emissions. The implementation of this system promises to enhance Oman's economic and transportation industries by promoting the adoption of electric and fuel cell vehicles while reducing reliance on traditional energy sources.
Low to Near-zero CO2 Production of Hydrogen from Fossil Fuels: Critical Role of Microwave-initiated Catalysis
Apr 2025
Publication
Presently there is no single clear route for the near-term production of the huge volumes of CO2-free hydrogen necessary for the global transition to any type of hydrogen economy. All conventional routes to produce hydrogen from hydrocarbon fossil fuels (notably natural gas) involve the production—and hence the emission—of CO2 most notably in the steam methane reforming (SMR) process. Our recent studies have highlighted another route; namely the critical role played by the microwave-initiated catalytic pyrolysis decomposition or deconstruction of fossil hydrocarbon fuels to produce hydrogen with low to near-zero CO2 emissions together with high-value solid nanoscale carbonaceous materials. These innovations have been applied firstly to wax then methane crude oil diesel then biomass and most recently Saudi Arabian light crude oil as well as plastics waste. Microwave catalysis has therefore now emerged as a highly effective route for the rapid and effective production of hydrogen and high-value carbon nanomaterials co-products in many cases accompanied by low to near-zero CO2 emissions. Underpinning all of these advances has been the important concept from solid state physics of the so-called Size-Induced-Metal-Insulator Transition (SIMIT) in mesoscale or mesoscopic particles of catalysts. The mesoscale refers to a range of physical scale in-between the micro- and the macro-scale of matter (Huang W Li J and Edwards PP 2018 Mesoscience: exploring the common principle at mesoscale Natl. Sci. Rev. 5 321-326 (doi:10.1093/nsr/nwx083)). We highlight here that the actual physical size of the mesoscopic catalyst particles located close to the SIMIT is the primary cause of their enhanced microwave absorption and rapid heating of particles to initiate the catalytic—and highly selective—breaking of carbon–hydrogen bonds in fossil hydrocarbons and plastics to produce clean hydrogen and nanoscale carbonaceous materials. Importantly also since the surrounding ‘bath’ of hydrocarbons is cooler than the microwave-heated catalytic particles themselves the produced neutral hydrogen molecule can quickly diffuse from the active sites. This important feature of microwave heating thereby minimizes undesirable side reactions a common feature of conventional thermal heating in heterogeneous catalysis. The low to near-zero CO2 production of hydrogen via microwave-initiated decomposition or cracking of abundant hydrocarbon fossil fuels may be an interim viable alternative to the conventional widely-used SMR that a highly efficient process but unfortunately associated with the emission of vast quantities of CO2. Microwave-initiated catalytic decomposition also opens up the intriguing possibility of using distributed methane in the current natural gas structure to produce hydrogen and high-value solid carbon at either central or distributed sites. That approach will lessen many of the safety and environmental concerns associated with transporting hydrogen using the existing natural gas infrastructure. When completely optimized microwave-initiated catalytic decomposition of methane (and indeed all hydrocarbon sources) will produce no aerial carbon (CO2) and only solid carbon as a co-product. Furthermore reaction conditions can surely be optimized to target the production of high-quality synthetic graphite as the major carbon-product; that material of considerable importance as the anode material for lithium-ion batteries. Even without aiming for such products derived from the solid carbon co-product it is of course far easier to capture solid carbon rather than capturing gaseous CO2 at either the central or distributed sites. Through microwave-initiated catalytic pyrolysis this decarbonization of fossil fuels can now become the potent source of sustainable hydrogen and high-value carbon nanomaterials.
Microwaves in Clean Energy Technologies
Mar 2025
Publication
Energy in the microwave spectrum is increasingly applied in clean energy technologies. This review discusses recent innovations using microwave fields in hydrogen production and synthesis of new battery materials highlighting the unique properties of microwave heating. Key innovations include microwave-assisted hydrogen generation from water hydrocarbons and ammonia and the synthesis of high-performance anode and cathode materials. Microwave-assisted catalytic water splitting using Gd-doped ceria achieves efficient hydrogen production below 250°C. For hydrocarbons advanced microwave-active catalysts Fe–Ni alloys and ruthenium nanoparticles enable high conversion rates and hydrogen yields. In ammonia synthesis microwaves reduce the energy demands of the Haber–Bosch process and enhance hydrogen production efficiency using catalysts such as ruthenium and Co2Mo3N. In battery technology microwave-assisted synthesis of cathode materials like LiFePO4 and LiNi0.5Mn1.5O4 yields high-purity materials with superior electrochemical performance. Developing nanostructured and composite materials including graphene-based anodes significantly improves battery capacities and cycling stability. The ability of microwave technology to provide rapid selective heating and enhance reaction rates offers significant advancements in clean energy technologies. Ongoing research continues to bridge theoretical understanding and practical applications driving further innovations in this field. This review aims to highlight recent advances in clean energy technologies based upon the novel use of microwave energy. The potential impact of these emerging applications is now being fully understood in areas that are critical to achieving net zero and can contribute to the decarbonization of key sectors. Notable in this landscape are the sectors of hydrogen fuel and battery technologies. This review examines the role of microwaves in these areas.
An Optimal Approach to the Pre-Implementation Value Assessment of Smart Energy Systems; A 'Green' Hydrogen Case Study
Aug 2025
Publication
Smart energy systems can be used to generate additional financial value by providing flexibility to the electricity network. It is fundamental to the effective economic implementation of these systems that an assessment can be made in advance to determine available value in comparison with any additional costs. The basic premise is that there is a distinct advantage in using similar algorithms to an actual smart energy system implementation for value assessment and that this is practical in this context which is confirmed in comparison with simpler modelling methods. Analysis has been undertaken using a ‘green’ hydrogen system case study of the impact of various simplifications to the value assessment algorithms used to speed computation time without sacrificing the decisionmaking potential of the output. The results indicate that for localised energy systems with a small number of controllable assets an rolling horizon optimisation model with a significant degree of temporal and component complexity is viable for planning phase value assessment requirements and would be a similar level of complexity to a computationally suitable implementation algorithm for actual asset control decision making.
Off-grid Shore-to-ship Power System Optimisation with a Hydrogen-in-loop Buffering Scheme Drien by Hydrokinetic Wave-wind Energy
Oct 2025
Publication
The environmentally vulnerable Arctic’s harsh climate and remote geography demand innovative green energy solutions. This study introduces a hybrid off-grid system that integrates wave and wind energy with hydrogenelectricity conversion technologies. Designed to power cruise ships at berth fuel-cell hybrid electric vehicles and residential heating the system tackles the challenge of energy variability through dual optimization schemes. External optimization identifies a cost-effective architecture achieving a net present cost of $1.1M and a levelized hydrogen cost of $20.1/kg without a fuel cell. Internal optimizations employing multi-objective game theory and HYBRID algorithms further improve performance reducing the net present cost to $666K with a levelized hydrogen cost of $13.74/kg (game theory) and $729K with a levelized hydrogen of $15.63/kg (HYBRID). A key innovation is hydrokinetic turbines which streamline the design by cutting cumulative cash flow requirements by $470K from $1.85M to $1.38M. This approach prioritizes intelligent energy management shifting reliance from variable wind and wave inputs to optimized electrolyzer and battery operations. These results underscore the feasibility of cost-effective and scalable renewable energy systems and provide a compelling blueprint for addressing energy challenges in remote and resource-constrained environments.
Magnetically Induced Convection Enhances Water Electrolysis in Microgravity
Aug 2025
Publication
Since the early days of space exploration the efficient production of oxygen and hydrogen via water electrolysis has been a central task for regenerative life-support systems. Water electrolysers are however challenged by the near-absence of buoyancy in microgravity resulting in hindered gas bubble detachment from electrodes and diminished electrolysis efficiencies. Here we show that a commercial neodymium magnet enhances water electrolysis with current density improvements of up to 240% in microgravity by exploiting the magnetic polarization of the electrolyte and the magnetohydrodynamic force. We demonstrate that these interactions enhance gas bubble detachment and displacement through magnetic convection and achieve passive gas–liquid phase separation. Two model magnetoelectrolytic cells a proton-exchange membrane electrolyser and a magnetohydrodynamic drive were designed to leverage these forces and produce oxygen and hydrogen at near-terrestrial efficiencies in microgravity. Overall this work highlights achievable lightweight low-maintenance and energy-efficient phase separation and electrolyser technologies to support future human spaceflight architectures.
Analysis of Floating Photovoltaics Potential in Hong Kong: Green Hydrogen Production and Energy Application
Oct 2025
Publication
Solar energy is now one of the most affordable and widely available energy sources. However densely populated cities like Hong Kong often lack the land needed for large-scale solar deployment. Floating solar photovoltaics (FPV) offer a promising alternative by using water surfaces such as reservoirs while providing additional benefits over ground-mounted systems including competition with urban development such as housing and infrastructure. The advantage of this system has been explored in parts of the world while Hong Kong is yet to fully exploit it despite the presence of pilot projects. This study uses PVsyst to evaluate FPV deployment across Hong Kong’s reservoirs estimating over 7 TWh of potential annual electricity generation. Even with 60 % surface coverage generation reaches 4.6 TWh/year with LCOE between $0.036–$0.038/kWh. In parallel green hydrogen is explored as a clean energy storage solution and alternative transport fuel. By using electricity from FPV systems hydrogen production via electrolysis is assessed through HOMER Pro. Results show annual hydrogen output ranging from 180502 kg to 36310221 kg depending on reservoir size with associated LCOH between $10.2/kg and $19.4/kg. The hydrogen produced could support ongoing hydrogen bus projects and future expansion to other vehicle types as Hong Kong moves toward a hydrogen-based transport system. After coupling the FPV systems with hydrogen-generation units the new LCOEs are found to be between $0.029–4.01/ kWh. Thus suggesting the feasibility of a hydrogen-integrated FPV system in Hong Kong.
IEA TCP Task 43 - Recommendations for Safety Distances Methodology for Alkaline and PEM Electrolyzers
Sep 2025
Publication
Elena Vyazmina,
Richard Chang,
Benjamin Truchot,
Katrina M. Groth,
Samantha E. Wismer,
Sebastien Quesnel,
David Torrado,
Nicholas Hart,
Thomas Jordan,
Karen Ramsey-Idem,
Deborah Houssin-Agbomson,
Simon Jallais,
Christophe Bernard,
Lucie Bouchet,
Ricardo Ariel Perez,
Lee Phillips,
Marcus Runefors,
Jerome Hocquet and
Andrei V. Tchouvelev
Currently local regulations governing hydrogen installations vary by geographical region and by country leading to discrepancies in safety and separation distance requirements for similar hydrogen systems. This work carried out in the frame of IEA TCP H2 Task 43 (IEA TCP H2 2022) aims to provide an overview of various methodologies and recommendations established for risk management and consequence assessment in the event of accidental scenarios. It focuses on a case study involving industrial electrolyzers utilizing alkaline and PEM technologies. The research incorporates lessons learned from past incidents offers recommendations for mitigation measures reviews existing methodologies and highlights areas of divergence. Additionally it proposes strategies for harmonization. The study also emphasizes the most significant scenarios and the corresponding leakage sizes
Waste to Hydrogen: Steam Gasification of Municipal Solid wastes with Carbon Capture for Enhanced Hydrogen Production
Apr 2025
Publication
The research focuses on enhancing hydrogen production using a blend of municipal solid waste (MSW) with Biomass and mixed plastic waste (MPW) under the Bioenergy with Carbon Capture Utilisation and Storage (BECCUS) concept. The key challenges include optimising the feedstock blends and gasification process parameters to maximise hydrogen yield and carbon dioxide capture. This study introduces a novel approach that employs sorption-enhanced gasification and a high-temperature regenerator reactor. Using this method syngas streams with high hydrogen contents of up to 93 mol% and 66 mol% were produced respectively. Thermodynamic simulations with Aspen Plus® validated the integrated system for achieving high-purity hydrogen (99.99 mol%) and effective carbon dioxide isolation. The system produced 70.33 molH2 /kgfeed when using steam as a gasifying agent while 37.95 molH2 /kgfeed was produced under air gasification conditions. Case I employed a mixture of MSW and wood residue at a ratio of 1:1.25 with steam and calcium oxide added at 2:1 and 0.92:1 respectively resulting in 68.80 molH2 /kgfeed and a CO2 capture efficiency of 92 %. Case II utilised MSW and MPW at a 1:1 ratio with steam and calcium oxide at 2:1 and 0.4:1 respectively producing 100.17 molH2 /kgfeed and achieving a 90.09 % CO2 capture efficiency. The optimised parameters significantly improve hydrogen yield and carbon capture offering valuable insights for BECCUS applications.
Integrated Energy Storage and Transmission Solutions: Evaluating hydrogen, Ammonia, and Compressed Air for Offshore Wind Power Delivery
Mar 2025
Publication
This paper introduces a novel dual-purpose transmission system that integrates power transmission and energy storage using hydrogen ammonia and compressed air—an area largely unexplored in the literature. Unlike conventional cable transmission which requires separate storage infrastructure the proposed approach leverages the transmission medium itself as an energy storage solution enhancing system efficiency and reducing costs. By incorporating a defined storage allocation factor this study examines the delivery of offshore-generated power to onshore locations calculating the necessary media flow rates and evaluating the required transportation infrastructure including tunnels and pipelines. A comparative cost-effectiveness analysis is conducted to determine optimal conditions under which storage-integrated transmission outperforms conventional cable transmission. Various transmission powers storage fractions pressures and distances are analysed to assess feasibility and economic viability. The findings indicate that for a 75 % storage allocation factor compressed air can transmit up to 450 MW over 300 km more cost-effectively than cables while hydrogen enables 230 MW transmission beyond 310 km. Ammonia proves to be the most efficient facilitating the transmission of over 2000 MW across distances exceeding 140 km at a lower cost than cables all without requiring onshore storage. Moreover for a 500-km transmission line compressed air hydrogen and ammonia can store the equivalent of 62 58 and 152 h of wind farm output respectively significantly reducing the need for additional onshore storage. This study fills a critical research gap by optimizing offshore wind power delivery through an innovative cost-effective and scalable transmission and storage approach.
The Link Between Microstructural Heterogeneity and Hydrogen Redistribution
Jul 2025
Publication
Green hydrogen is likely to play a major role in decarbonising the aviation industry. It is crucial to understand the effects of microstructure on hydrogen redistribution which may be implicated in the embrittlement of candidate fuel system metals. We have developed a multiscale finite element modelling framework that integrates micromechanical and hydrogen transport models such that the dominant microstructural effects can be efficiently accounted for at millimetre length scales. Our results show that microstructure has a significant effect on hydrogen localisation in elastically anisotropic materials which exhibit an interesting interplay between microstructure and millimetre-scale hydrogen redistribution at various loading rates. Considering 316L stainless steel and nickel a direct comparison of model predictions against experimental hydrogen embrittlement data reveals that the reported sensitivity to loading rate may be strongly linked with rate-dependent grain scale diffusion. These findings highlight the need to incorporate microstructural characteristics in hydrogen embrittlement models.
Feasibility Assessment into the Use of Hybrid Gas-hydride Tanks for Use in Improving the Flexibility of Offshore Hydrogen Production using Wind Power
Oct 2025
Publication
Offshore hydrogen production offers a promising solution for harnessing wind energy far from shore by using hydrogen as an energy carrier instead of electrical cables. Flexibility in hydrogen production systems is crucial to maximising the conversion of intermittent wind energy into hydrogen. To improve the performance of lowpressure compressed gas buffer stores hybrid gas-hydride tanks have been identified as a viable solution increasing useable storage density from 1.2 kg m− 3 to 6.3 kg m− 3 with just a 5 vol% addition of hydride. This study evaluates the reduction in tank volume reduction in cost and enhancements in useable storage density achieved by integrating different hydrides under varying temperature conditions. Using hydrogen mass flow rate profiles a storage mass target was determined for optimisation. The results demonstrate that hybrid gas-hydride tanks can reduce tank size by around 80 % lowering costs by 24 % and achieve a 5.1-fold improvement in useable storage density.
Green Hydrogen Viability in the Transition to a Fully-Renewable Energy Grid
Sep 2025
Publication
With the transition to a fully renewable energy grid arises the need for a green source of stability and baseload support which classical renewable generation such as wind and solar cannot offer due to their uncertain and highly-variable generation. In this paper we study whether green hydrogen can close this gap as a source of supplemental generation and storage. We design a two-stage mixed-integer stochastic optimization model that accounts for uncertainties in renewable generation. Our model considers the investment in renewable plants and hydrogen storage as well as the operational decisions for running the hydrogen storage systems. For the data considered we observe that a fully renewable network driven by green hydrogen has a greater potential to succeed when wind generation is high. In fact the main investment priorities revealed by the model are in wind generation and in liquid hydrogen storage. This long-term storage is more valuable for taking full advantage of hydrogen than shorter-term intraday hydrogen gas storage. In addition we note that the main driver for the potential and profitability of green hydrogen lies in the electricity demand and prices as opposed to those for gas. Our model and the investment solutions proposed are robust with respect to changes in the investment costs. All in all our results show that there is potential for green hydrogen as a source of baseload support in the transition to a fully renewable-powered energy grid.
Decarbonising Agriculture with Green Hydrogen: A Stakeholder Guided Feasibility Study
Oct 2025
Publication
Green hydrogen offers a promising yet underexplored pathway for agricultural decarbonisation requiring technological readiness and coordinated action from policymakers industry and farmers. This paper integrates techno-economic modelling with stakeholder engagement (semi-structured interviews and an expert workshop) to assess its potential. Analyses were conducted for farms of 123 hectares and clusters of 10 farms complemented by seven interviews and a workshop with nine sector experts. Findings show both opportunities and barriers. While on-farm hydrogen production is technically feasible it remains economically uncompetitive due to high levelised costs shaped by seasonal demand variability and low utilisation of electrolysers and storage. Pooling demand across multiple users is essential to improve cost-effectiveness. Stakeholders identified three potential business models: fertiliser production via ammonia synthesis cooperative-based models and local refuelling stations. Of these cooperative hydrogen hubs emerged as the most promising enabling clusters of farms to jointly invest in renewable-powered electrolysers storage and refuelling facilities thereby reducing costs extending participation to smaller farms and mitigating risks through collective investment. By linking techno-economic feasibility with stakeholder perspectives and business model considerations the results contribute to socio-technical transition theory by showing how technological institutional and social factors interact in shaping hydrogen adoption in agriculture. With appropriate policy support cooperative hubs could lower costs ease concerns over affordability and complexity and position hydrogen as a practical driver of agricultural decarbonisation and rural resilience. Keywords: green
Exploring the Potential of Ammonia as a Fuel: Advances in Combustion Understanding and Large-scale Furnace Applications
Sep 2025
Publication
From an environmental standpoint carbon-free energy carriers such as ammonia and hydrogen are essential for future energy systems. However their hightemperature chemical behavior remains insufficiently understood posing challenges for the development and optimization of advanced combustion technologies. Ammonia in particular is globally available and cost-effective especially for energy-intensive industries. The addition of ammonia or hydrogen to methane significantly reduces the accuracy of existing predictive models. Therefore validated and detailed data are urgently needed to enable reliable design and performance predictions. This review highlights the compatibility of ammonia with existing combustion infrastructure facilitating a smoother transition to more sustainable heating methods without the need for entirely new systems. Applications in high-temperature heating processes such as metal processing ceramics and glass production and power generation are of particular interest. This review focuses on the systematic assessment of alternative fuel mixtures comprising ammonia and hydrogen as well as natural gas with particular consideration of existing safety-related parameters and combustion characteristics. Fundamental quantities such as the laminar burning velocity are discussed in the context of their relevance for fuel mixtures and their scalability toward turbulent flame propagation which is of critical importance for industrial burner and reactor design. The influence of fuel composition on ignition limits is examined as these are essential parameters for safety margin definitions and operational boundary conditions. Furthermore flame stability in mixed-fuel systems is addressed to evaluate the practical feasibility and robustness of combustion under varying process conditions. A detailed overview of current diagnostic and analysis methods follows encompassing both pollutant measurement techniques and the detection of key radical species. These diagnostics form the experimental basis for reaction kinetics modeling and mechanism validation. Given the importance of emission formation in combustion systems a dedicated subsection summarizes major emission trends even though a comprehensive treatment would exceed the scope of this review. Thermal radiation effects which are highly relevant for heat transfer and system efficiency in large-scale applications are then reviewed. In parallel current developments in numerical simulation approaches for industrial-scale combustion systems are presented including aspects of model accuracy boundary conditions and computational efficiency. The review also incorporates insights from materials engineering particularly regarding high-temperature material performance corrosion resistance and compatibility with combustion products. Based on these interdisciplinary findings operational strategies for high-temperature furnaces are outlined and selected industrial reference systems are briefly presented. This integrated approach aims to support the design optimization and safe operation of next-generation combustion technologies utilizing carbon-free or low-carbon fuels.
Energy Storage in the Energy Transition and Blue Economy: Challenges, Innovations, Future Perspectives, and Educational Pathways
Sep 2025
Publication
Transitioning to renewable energy is vital to achieving decarbonization at the global level but energy storage is still a major challenge. This review discusses the role of energy storage in the energy transition and the blue economy focusing on technological development challenges and directions. Effective storage is vital for balancing intermittent renewable energy sources like wind solar and marine energy with the power grid. The development of battery technologies hydrogen storage pumped hydro storage and emerging technologies like sodium-ion and metal-air batteries is discussed for their potential for large-scale deployment. Shortages in critical raw materials environmental impact energy loss and costs are some of the challenges to large-scale deployment. The blue economy promises opportunities for offshore energy storage notably through ocean thermal energy conversion (OTEC) and compressed air energy storage (CAES). Moreover the capacity of datadriven optimization and artificial intelligence to enhance storage efficiency is discussed. Policy interventions and economic incentives are necessary to spur the development and deployment of sustainable energy storage technology. Education and workforce training are also important in cultivating future researchers engineers and policymakers with the ability to drive energy innovation. Merging sustainability training with an interdisciplinary approach can potentially establish an efficient workforce that is capable of addressing energy issues. Future work needs to focus on higher energy density efficiency recyclability and cost-effectiveness of the storage technologies without sacrificing their environmental sustainability. The study underlines the need for converging technological economic and educational approaches to enable a sustainable and resilient energy future.
Techno-Economic Environmental Risk Analysis (TERA) in Hydrogen Farms
Sep 2025
Publication
This study presents a techno-economic environmental risk analysis (TERA) of large-scale green hydrogen production using Alkaline Water Electrolysis (AWE) and Proton Exchange Membrane (PEM) systems. The analysis integrates commercial data market insights and academic forecasts to capture variability in capital expenditure (CAPEX) efficiency electricity cost and capacity factor. Using Libya as a case study 81 scenarios were modelled for each technology to assess financial and operational trade-offs. For AWE CAPEX is projected between $311 billion and $905.6 billion for 519 GW (gigawatts) of installed capacity equivalent to 600–1745 $/kW. PEM systems show a wider range of $612 billion to $1020 billion for 510 GW translating to 1200–2000 $/kW. Results indicate that AWE while requiring greater land use provides significant cost advantages due to lower capital intensity and scalability. In contrast PEM systems offer compact design and operational flexibility but at substantially higher costs. The five most economical scenarios for both technologies consistently feature low CAPEX and high efficiency while sensitivity analyses confirm these two parameters as the dominant cost drivers. The findings emphasise that technology choice should reflect context-specific priorities such as land availability budget and performance needs. This study provides actionable guidance for policymakers and investors developing cost-effective hydrogen infrastructure in emerging green energy markets.
Modeling Porosity Distribution Strategies in PEM Water Electrolyzers: A Comparative Analytical and Numerical Study
Jun 2025
Publication
Proton exchange membrane water electrolyzers (PEMWEs) are a promising technology for green hydrogen production. However the adoption of PEMWE-based hydrogen production systems remains limited due to several challenges including high material costs limited performance and durability and difficulties in scaling the technology. Computational modeling serves as a powerful tool to address these challenges by optimizing system design improving material performance and reducing overall costs thereby accelerating the commercial rollout of PEMWE technology. Despite this conventional models often oversimplify key components such as porous transport and catalyst layers by assuming constant porosity and neglecting the spatial heterogeneity found in real electrodes. This simplification can significantly impact the accuracy of performance predictions and the overall efficiency of electrolyzers. This study develops a mathematical framework for modeling variable porosity distributions—including constant linearly graded and stepwise profiles—and derives analytical expressions for permeability effective diffusivity and electrical conductivity. These functions are integrated into a three-dimensional multi-domain COMSOL simulation to assess their impact on electrochemical performance and transport behavior. The results reveal that although porosity variations have minimal effect on polarization at low voltages they significantly influence internal pressure species distribution and gas evacuation at higher loads. A notable finding is that reversing stepwise porosity—placing high porosity near the membrane rather than the channel—can alleviate oxygen accumulation and improve current density. A multi-factor comparison highlights this reversed configuration as the most favorable among the tested strategies. The proposed modeling approach effectively connects porous media theory and systemlevel electrochemical analysis offering a flexible platform for the future design of porous electrodes in PEMWE and other energy conversion systems.
Influence of Engine Oils on Pre-Ignition Tendency in a Hydrogen–Kerosene Dual-Fuel Engine
Mar 2025
Publication
Reducing CO2 emissions is an increasingly important goal in general aviation. The dual-fuel hydrogen–kerosene combustion process has proven to be a suitable technology for use in small aircraft. This robust and reliable technology significantly reduces CO2 emissions due to the carbon-free combustion of hydrogen during operation while pure kerosene or sustainable aviation fuel (SAF) can be used in safety-critical situations or in the event of fuel supply issues. Previous studies have demonstrated the potential of this technology in terms of emissions performance and efficiency while also highlighting challenges related to abnormal combustion phenomena such as knocking and pre-ignition which limit the maximum achievable hydrogen energy share. However the causes of such phenomena—especially regarding the role of lubricating oils—have not yet been sufficiently investigated in hydrogen engines making this a crucial area for further development. In this paper investigations at the TU Wien Institute of Powertrain and Automotive Technology concerning the role of different engine oils in influencing pre-ignition tendencies in a hydrogen–kerosene dual-fuel engine are described. A specialized test procedure was developed to account for the unique combustion characteristics of the dual-fuel process along with a detailed purge procedure to minimize oil carryover. Multiple engine oils with varying compositions were tested to evaluate their influence on pre-ignition tendencies with a particular focus on additives containing calcium magnesium and molybdenum known for their roles in detergent and anti-wear properties. Additionally the study addressed the contribution of particles to pre-ignition occurrences. The results indicate that calcium and magnesium exhibit no notable impact on pre-ignition behavior; however the addition of molybdenum results in a pronounced reduction in pre-ignition events which could enable a higher hydrogen energy share and thus decrease CO2 emissions in the context of hydrogen dual-fuel aviation applications.
A Priori and a Posteriori Analyses of Differential and Preferential Diffusion in Large Eddy Simulations of Partially Premixed Hydrogen-air Flames
Oct 2025
Publication
Differential diffusion (DD) and non-unity Lewis number (Le) effects in the filtered equations of the mixture fraction progress variable their respective sub-grid scale (SGS) variances and enthalpy are investigated using a priori and a posteriori analyses of a lifted turbulent hydrogen jet flame. The a priori analyses show that the absolute magnitudes of the DD terms in the filtered mixture fraction equation and its SGS variance are significant individually but their net contribution is small. The DD effects are found to be small for the progress variable and its SGS variance. One non-unity Le term is of similar magnitude to the turbulent flux for the filtered enthalpy and is independent of turbulent transport. Therefore a simple model for this effect is constructed using flamelets. A priori validation of this model is performed using direct numerical simulation data of a lifted hydrogen flame and its a posteriori verification is undertaken through two large eddy simulations. This effect influences the enthalpy field and hence the temperature is affected because of the relative increase (decrease) in thermal diffusivity for lean (rich) mixtures. Hence higher peak temperatures are observed in the rich mixture when the non-unity Le effects are included. However its overall effects on the flame lift-off height and flame-brush structure are observed to be small when compared with measurements. Hence the DD and non-unity Le effects are negligible for LES of partially premixed combustion of hydrogen–air mixtures in high Reynolds number flows. Novelty and significance The relative importance of differential and preferential diffusion effects for large eddy simulations using the tabulated chemistry approach is systematically assessed. The consistency among the complete set of equations and their closure models of the controlling variables (filtered mixture fraction progress variable their subgrid scale variances and enthalpy) for partially premixed combustion is maintained on the physical and mathematical grounds for the first time. The novelty of this work lies in the development validation and verification of a computationally simple yet accurate and robust model for these diffusion effects and its a priori and a posteriori analyses. It is demonstrated that the influence of non-equidiffusion is small for turbulent partially premixed hydrogen–air flames and hence the standard unity Lewis number approach is shown to be sufficient for turbulent partially premixed flames with high turbulence levels which are typical in practical applications.
Fuel Cell and Electric Vehicles: Resource Use and Associated Environmental Impacts
Oct 2025
Publication
Achieving transport decarbonization depends on electric vehicle (EV) and fuel cell vehicle (FCV) deployment yet their material demands and impacts vary by vehicle type. This study explores how powertrain preferences in light-duty vehicles (LDVs) and heavy-duty vehicles (HDVs) shape future resource use and material-related environmental outcomes. Using dynamic material flow analysis and prospective life cycle assessment we assess three scenarios. In the S3 EV-dominant scenario 2050 lithium and cobalt demand rises by up to 11.9-fold and 1.8-fold relative to 2020 with higher global warming and human toxicity impacts. The S2 FCV-dominant scenario leads to a 21.7-fold increase in platinum-group metal demand driving up freshwater ecotoxicity and particulate emissions. A balanced S1 scenario EVs in LDVs and FCVs in HDVs yields moderate material demand and environmental burdens. These findings demonstrate that no single pathway can fully resolve material-related impacts while combining EVs and FCVs across LDVs and HDVs enables a more balanced and sustainable transition.
From Investment to Impact: Exploring Socio-economic Prospect of Hydrogen Investment in Tees Valley, UK
Oct 2025
Publication
Financial viability is fundamental for investment success however long run sustainable investment relies on delivering tangible socio-economic benefits that foster societal acceptance enhancing community welfare and well-being. This study developed a quantitative model to evaluate the socio-economic impact of a proposed 1 GW green and 2 GW blue hydrogen investment in Tees Valley UK from 2027 to 2035. We introduced the socioeconomic impact (SEI) ratio defined as the ratio of socio-economic impact to the Levelized Cost of Hydrogen (LCOH) to illustrate the significance of socio-economic impact beyond financial returns. Findings indicate that the cumulative environmental and economic impact of green hydrogen amounted to £1.5 ± 0.5 bn and £1.35 ± 0.27 bn respectively with an employment impact of £269 ± 28 mn. In contrast the proposed blue hydrogen investment is expected to deliver £2.9 ± 0.9 bn environmental impact £1.84 ± 0.37 bn economic impact and £212 ± 26 mn employment social impact. The SEI ratio of green hydrogen was found to range between 48 % and 62 % and 60 %–79 % for blue hydrogen suggesting overall SEI ratio of approximately 60 % for combined green and blue investment. Sensitivity analysis using Monte Carlo simulation revealed that the results are particularly sensitive to the Gross Value Added (GVA) emission and employment factors. These findings highlight the importance of integrating socio-economic considerations into hydrogen planning investment strategies and decision-making to optimise environmental societal and economic outcomes.
Application and Research Progress of Mechanical Hydrogen Compressors in Hydrogen Refueling Stations: Structure, Performance, and Challenges
Nov 2025
Publication
The hydrogen energy industry is rapidly developing positioning hydrogen refueling stations (HRSs) as critical infrastructure for hydrogen fuel cell vehicles. Within these stations hydrogen compressors serve as the core equipment whose performance and reliability directly determine the overall system’s economy and safety. This article systematically reviews the working principles structural features and application status of mechanical hydrogen compressors with a focus on three prominent types based on reciprocating motion principles: the diaphragm compressor the hydraulically driven piston compressor and the ionic liquid compressor. The study provides a detailed analysis of performance bottlenecks material challenges thermal management issues and volumetric efficiency loss mechanisms for each compressor type. Furthermore it summarizes recent technical optimizations and innovations. Finally the paper identifies current research gaps particularly in reliability hydrogen embrittlement and intelligent control under high-temperature and high-pressure conditions. It also proposes future technology development pathways and standardization recommendations aiming to serve as a reference for further R&D and the industrialization of hydrogen compression technology.
Optimal Sizing and Energy Management for Fuel Cell Electric Vehicles with 3D-ordered MEAs: A Pareto Frontier Study
Oct 2025
Publication
Fuel cell electric vehicles (FCEVs) are zero-emission but face cost and power density challenges. To mitigate these limitations a novel 3D-ordered nano-structured self-supporting membrane electrode assembly (MEA) has been developed. This paper investigates the optimal component sizing of the battery and fuel cell in FCEVs equipped with 3D-ordered MEAs integrating the energy management. To explore the trade-offs between component cost operational cost and fuel cell degradation the sizing and energy management problem is formulated into a multi-objective optimisation problem. A Pareto frontier (PF) study is conducted using the decomposed multi-objective evolutionary algorithm (MOEA/D) for a more diverse distribution of feasible solutions. The modular design of fuel cells is derived from a scaled and stressed experiment. After executing MOEA/D across the three aggressive driving cycles power source configurations are selected from the corresponding PFs based on objective trade-offs ensuring robustness of the overall system. The optimisation performance of the MOEA/D is compared with that of the multi-objective Particle Swarm Optimisation. In addition the selected powertrain configurations are evaluated and compared through standard and realworld driving cycles in a simulation environment. This paper also performs a sensitivity analysis to reveal the influence of diverse component unit costs and hydrogen price. The results indicate that the mediumsized configuration consisting of a 63.31 kW fuel cell stack and a 52.15 kWh battery pack delivers the best overall performance. It achieves a 26.71% reduction in component cost and up to 12.76% savings in hydrogen consumption across various driving conditions. These findings provide valuable insights into the design and optimisation of fuel cell systems for FCEVs.
Cutting-edge Advances in Hydrogen Applications for the Medical and Pharmaceutical Industries
Oct 2025
Publication
The adoption of clean hydrogen is expected to transform the global energy landscape reducing greenhouse gas emissions bridging gaps in renewable energy integration and driving innovation across multiple sectors. In the medical and pharmaceutical industries hydrogen offers unique opportunities for transformative progress. This review critically examines recent advances in three domains: hydrogen fuel cells as reliable scalable and sustainable energy solutions for hospitals; molecular hydrogen as a therapeutic and preventive medical gas particularly for brain disorders; and hydrogenation technologies for the efficient and sustainable pharmaceutical production. Despite encouraging advancements widespread adoption remains limited by economic constraints regulatory gaps and limited clinical evidence. Addressing these barriers through technological innovation largescale studies and life-cycle sustainability assessments is essential to translate hydrogen’s full potential into clinical and industrial practice. Responsible adoption of green hydrogen is poised to reshape the clinical approach to global health and enhance the quality of life for people worldwide.
Marine Hydrogen Pressure Reducing Valves: A Review on Multi-Physics Coupling, Flow Dynamics, and Structural Optimization for Ship-Borne Storage Systems
Oct 2025
Publication
As a zero-carbon energy carrier hydrogen is playing an increasingly vital role in the decarbonization of maritime transportation. The hydrogen pressure reducing valve (PRV) is a core component of ship-borne hydrogen storage systems directly influencing the safety efficiency and reliability of hydrogen-powered vessels. However the marine environment— characterized by persistent vibrations salt spray corrosion and temperature fluctuations— poses significant challenges to PRV performance including material degradation flow instability and reduced operational lifespan. This review comprehensively summarizes and analyzes recent advances in the study of high-pressure hydrogen PRVs for marine applications with a focus on transient flow dynamics turbulence and compressible flow characteristics multi-stage throttling strategies and valve core geometric optimization. Through a systematic review of theoretical modeling numerical simulations and experimental studies we identify key bottlenecks such as multi-physics coupling effects under extreme conditions and the lack of marine-adapted validation frameworks. Finally we conducted a preliminary discussion on future research directions covering aspects such as the construction of coupled multi-physics field models the development of marine environment simulation experimental platforms the research on new materials resistant to vibration and corrosion and the establishment of a standardized testing system. This review aims to provide fundamental references and technical development ideas for the research and development of high-performance marine hydrogen pressure reducing valves with the expectation of facilitating the safe and efficient application and promotion of hydrogen-powered shipping technology worldwide.
Insights from Swirl Number and Ambient Pressure Variations with a Hydrogen/Ammonia Swirl Stabilized Diffusion Flame
Oct 2025
Publication
Contemporary research into decarbonized fuels such as H2/NH3 has highlighted complex challenges with applied combustion with marked changes in thermochemical properties leading to significant issues such as limited operational range flashback and instability particularly when attempts are made to optimize emissions production in conventional lean-premixed systems. Non-premixed configurations may address some of these issues but often lead to elevated NOx production particularly when ammonia is retained in the fuel mixture. Optimized fuel injection and blending strategies are essential to mitigate these challenges. This study investigates the application of a 75 %/25 %mol H2/NH3 blend in a swirl-stabilized combustor operated at elevated conditions of inlet temperature (500 K) and ambient pressure (0.11–0.6 MPa). A complex nonmonotonic relationship between swirl number and increasing ambient combustor pressure is demonstrated highlighting the intricate interplay between swirling flow structures and reaction kinetics which remains poorly understood. At medium swirl (SN = 0.8) an increase in pressure initially reduces NO emissions diminishing past ~0.3 MPa with an opposing trend evident for high swirl (SN = 2.0) as NO emissions fall rapidly when combustor pressure approaches 0.6 MPa. High-fidelity numerical modeling is presented to elucidate these interactions in detail. Numerical data generated using Detached Eddy Simulations (DES) were validated against experimental results to demonstrate a change in flame anchoring on the axial shear layer and marked change in recirculated flow structure successfully capturing the features of higher swirl number flows. Favorable comparisons are made with optical data and a reduction in NO emissions with increasing pressure is demonstrated to replicate changes to the swirling flame chemical kinetics. Findings provide valuable insights into the combustion behavior of hydrogen-rich ammonia flames contributing to the development of cleaner combustion technologies.
Sustainable Power System Transition Pathways: Regional Decarbonisation and Resource Conservation Aided by Small Modular Reactors
Oct 2025
Publication
Clean energy technologies offer promising pathways for low-carbon transitions yet their feasibility remains uncertain particularly in rapidly developing regions. This study develops a Factorial Multi-Stochastic Optimization-driven Equilibrium (FMOE) model to assess the economic and environmental impacts of clean power deployment. Using Small Modular Reactors (SMRs) in Guangdong China as a case study the model reveals that SMRs can reduce system costs and alleviate GDP losses supporting provincial-level Nationally Determined Contributions (NDCs). If offshore wind capital costs fall to 40 % of SMRs’ SMR deployment may no longer be necessary after 2030. Otherwise SMRs could supply 22 % of capacity by 2040. The FMOE model provides a robust adaptable framework for evaluating emerging technologies under uncertainty and supports sustainable power planning across diverse regional contexts. This study offers valuable insights into the resource and economic implications of clean energy strategies contributing to global carbon neutrality and efficient energy system design.
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